Telephone-receiver.



o. N. CHURCH: TELEPHONE RECEIVER. APPLICATION FILED-NOW 3, 1909.

Patented July 2, 1912.

$2 SHEETSSHEBT 1.

W N mama O. N. UHURGH. TELEPHONE RECEIVER.

APPLICATION FILED NOV. 3, 190a.-

Patented July 2, 1912.

2 SHEETS EET 2.

1 pngpg m Gwmmo I wmrlwm Wmmiz CHARLES N. CH'U RG11, 01 CAMDEN, NEW JERSEY.

TELEPHONE-BE CEIVER.

i narrate.

Specification of Letters Patent.

Patentct l July 2, liltB.

Applicat on filed November 3, 1909. Serial 1W0. 593,133.

To all whom it may concern.

lie it. known that l, CHARLES N. CHURCH, a citizen of the United States, residing at Camden, in the county of Camden and State of Nev; Jersey, have invented new and useful improvements in Telephone-Receivers, of which the following is a specification.

My invention relates to telephone receivers and its object is to produce a'receiver having very great sensitiveness and of incrcaF/ed power compared with those heretofore in use.

lly means of my invention 1 am enabled to greatly increase the strength ot the magnclic pull upon the telephone disk or dia phragm, and also to increase the amplitude of vibration due to the varying telephonic currents. I

This invention Will be clearly understood from the following description in connection with the accompanying drawings, in \vhich-- Figure 1 is a top-plan view of a receiver coustriu-tcd in accordance with one form of my invention, the ear-piece and diaphragm being removed; Fig. is a longitudinal reciioual view through the same With diaphragm and earpiece in position: F 3 is a similar view of a modified construction ot the receiver illustrated in Figs. 1 and :2; Fig. 4 is a top plan view of a receiver constructcd in accordance with anothertorm of my invention; Fig. 5 is a longitudinal sectional view through the same with the diaphragm and car-piccc. in position; Fig. 6 a Similar view of a modified construction of the receiver ,-ho\vii in l"ig. ;.--l and 5; Fig. 7 is a top plan view ol sti'l another form of my improved receiver; Fig. 8 is. a longitudinal sectional view of the same with the liaphragm and car-piece in position; Fig. .l is a similar vicu of a modified form of the receiver illustrated in l' igs. 7 and 5%: Fig. 10 is a top plan view of an improved Form of diaphragm: Fig. 11 is'a sectional view oi": the same: Fig. ill in a similar view of a modified Form of the diaphragm shown in Figs, 10 and ll and Figs: if-l, let, l5. l6, l7, l8. 19, 2O. .21. and 22 are sectional viewa ot' modified forms of diaphragme embodying my invention.

The magnetic lines of force induced in magnetic material not only vary with the number of turns of wire. the current being the same, but also according: to the proximity of the wire to the magnetic material forming the magnetic plate -l-.

rings or core structure tor-m winding spaced circuit. it is evident then that by bringing;' magnetic material forming the magnetic circuit the magnetic lines of force will be increased, and the ma netic pull upon the armature, which COIlSlltTlllES the diaphragm of the telephone receiver, will-he greatly enhanced, thereby increasing the sensitiveneoq of the telephone and its responsiveness to Weak currents. For thepurpose of utilizing this increased magnetic pull to etrengthen and increase the volume of sound, I comnine With this magnetic construction a compound diaphragm one portion of which re ceives the magnetic-pull and transmits the same to the center of the sound-producing portion, thereby largely increasing the amplitude of vibration of the latter. I also provide a means for equalizing the air-pressure upon the opposite sides of the diaphragm and permitting the free vibration thereof.

Referring now to the drawings and first to the construction shown in Figs. 1 and 2,

"the numeral 1 designates the casing of hardrubbcrorother suitable material of a telephone receiver of the Watch-case type. The car-piece 2 is secured to the tuning by screw-threading or in any suitable manner, and. clamps themain diaphragm 3 in position.

The magnetic structure of my receiver comprises a plate -lof magnetic material having projecting therefrom the central bar or rod and the concentric rings; The rod and rings may be integral with the plate 4 or may be suitably secured thereto or held in close contact therewith. The rodand concentric rings constitute the core FilIHC- ture of the iriagnetic syetem connected by means of a yoke piece i'zonetitutcd by the The annular spacerhctvvccn the which are completely filled with the insulated wire forming}; the magnet windings 7. The alternate windings or coils are wound and connected so that the electric current flows in opposite dircctions in adjacent coils and the coils are 'n'e'r'crahlv all connected in series. By means of this circuit arrange ment the current lowing at any instant. will cause :uljaccnt. concentric rings l to be of opposite polarity. the north and south magnetic poles alternating: in the ditlerent'rings.

it. will be apparent from this that. each ring will have induced therein magnetic fluxes the Wire'closer to the 'to keep the electric and the magnetic ele ments of the system in close proximity,

which enormously increases the efficiency and produces amaximum of flux lines for the number; of ampere turns of the magnet.

It willbe obvious from the above description that each ring forms the return magneticcircu t for the ad acent rings because they are-0f opposite polarities. The magnetic flux passing from one ring enters a portion of the diaphragm which lies just above these rings, viz: the auxiliary dia phragm ii Each magnetic circuit, therefore. is completed through the diaphragm, and is a nearly closed magnetic circuit producing the most eflicient magnetic system.

In order that I may use the great strength or pull of this magnetic system, I have devised a. compound diaphragm in which there is secured to the main diaphragm 3 an auxiliary diaphragm 3 rigidly secured thereto at the center. preferably by means of a tubular rivet which allows the free passageof the air from the inside to the outside of the diaphragm. The pull upon the auxiliary diaphragm 3 will be substantially uniform over its entire area, and the pull which is distributed over its entire face will be transmitted by means of the central rivet to the center of the outer or main sound producing diaphragm 3, and thus transmit a maximum amplitude of vibration to said outer diaphragm. By support ing the power-transmitting diaphragm 3 only at the'center, leaving its entire circmnference free from contact with the casing, I am enabled to secure a direct pull over the entire area and out to the veryfcircumferonce of the diaphragm 3*, and to transmit the combinedvpull due to the attraction of the several concentric magnetic circuits constituting my combined magnetic system.

In Fig. 4 I have shown a modification in which a. plurality of concentric magnetic elements are placed side by side, instead of 'arrangingall of the elements concentrically as in F g. 1(Instead of employing two magnetizing coils in each of the elements of the magnetic system'as' shown in Fig. 4, I

;may employ an arrangement such as shown 'qin'Fig. 7, in which each of the elements comprises a single magnetizing coil 7,

Wound around a central magnetic core 5 and surrounded'by a magnetic sleeve 6, each element thus constituting a complete magn et-icv circuit which is closed through the d aphragm. '-Instead .of using a shallow watch-case type of receiver, as shown in length. concentric rings of greater thickness at Figs. 2, 5, and I may extend the casing, as shown in Figs, 3, (i, and 9, and use a magnetic system having a greater core In this case I prefer to form the their inner ends joining the yokeplate 4,

,the outer portions being OI" reduced thickness, and the magnetizing coils being of a length sufiicient to extendonly over the reduced thinner portions of the magnetic rings or shells, illustrated. In all of the forms shown, I prefer to use a yoke-plate which is permanently magnetized, and it is preferable that the rods 5 andconcentric shells or rings fi should also .be likewise permanently magnetized, the adjacent being of opposite polarity, as previously explained. s

The main and auxiliary portions of the diaphragm may be secured together by means of a hollow rixjet 10, as shown in Figs. 1 and 5, or the parts may beimade integral or otherwise secured together, as shown in 8. I 1

Instead of constructingthe auxiiiary dis phragm 3 of asingle plate, as shown in Fig. 2, I may form the same of two or more plates secured together in the manner shown in 3, 6, and 9. In addition to the aperture or passage through the central portion of the combined diaphragm, I may also provide additional apertures shown in Figs. 3 and 6. By thus perforating the diaphragm the air pressure upon opposite sides is equalized at all times and the inner or auxiliary diaphragm is free to move within the chamber lying between the niain diaphragm 3 and the compound magnet.

Furthermore. in this manner, the vibrationsof the air within the chamber occupied by the auxiliary diaphragm are communicated to the outer air passage through the can piece and act to increase the volume of sound which transmitted. g.

In Figs. 10 to 22, I have ShOWIfW'HIlOLIS arrangements which may be employed in' constructing diaphragm in accordance with my present invention. Fig. 10 1s a plan view of which Fig. 11 is a cross-seotion, showing one manner of perforating the main diaphragm or disk. In Fig. '12, Lhaveshown the main gnd auxi'liary diaphragms secured ,by means of a solid rivet, both disks being perforated. In the re-- maining figures specified, I have shown diagrammatically in .erosssection a number of different-arrangements which may "be era-- ployed,'and in these constructionsl sometimes find it advisable to make portions or even the entire auxiliary diaphragm resiliem, as Well as the main diaphragm. In all ofthe constructions, however, it willbe ob served that the auxiliary power-transmitting diaphragm is connected'to the. main diaphragm only at the center, in which the amplitude oi vibration of the main dim phragin is greatest, the entire area of the auxiliary diaphragm being free to move loward and from the magnetic system.

'llheudvantages derived from my inveution' Will be appreciated by lllUH' skilled in this art. It will be apparent lilo; the 2ll'- rangement of concentric rings or sheets oi magnetic material to constitute the core or,

most dense. viz: close to the current-currying conductors. ll lloreover by the construction le scribed I am enabled. to use a larger number of turns of greater cross-section than in previous telephone receivers with which l am familiar, thereby securing a very large increase in the number 0t ainpere turns for the some value of ohmic resistance. Again, by means of my compound diaphragm. I am enabled to utilize the combined pull of the magnetic system which is distributed over the entire area. covered by the d1uphragm, instead of being exerted at one or two points as in the bar or horse-shoe magnets. As previously explained. the auxiliary diaphragm is unrestrained at its periphery and is free to move bodily toward and from the poles of the magnetic system and transmits the combined pull, which is the rcsultnnt'of several concentric magnets, to the center of the main diaphragm to thus enhance the-amplitude of vibration at the point oft maximum effect.

I have shown a number of different forms which may be used in the en'ibodiinent of my invention, but other modifications will occur to those skilled in this art and I do not Wish to be restricted. therefore, to the particular arrangement ot parts illustrated. intending to cover all changes which are embraced within the spirit of my invention and included within the scope of the appended claims;

Having described my invention, What itclaim and desire to secure by Letters Put cut, is-- 1521 telephone receiver comprising a magnetic system having a yoke plate, permanently magnetized in concentric bands alternating in polarity. and concentric rings of magnetic material projecting from said plate and coinciding with said magnetized bands. and magnetizing coils interposed between said rings. .7

l telephone receiver comprising a casino. :1 magnetic system therein having a plumlily oi con entricmagnetic elements and interposed magnetizing coils, said ele ments lit-tilllg adjacent-polar faces of oppof :1 main portion clamped site polarity. nu cur-piece secured lo sniil casing, and u compound diaphragm having bctwccu suiil curpiccc and said casing. and an auxiliary p rtion having a single central support secured to said main portion and lying closely adjacent to said magnetic system.

3. In a telephone rcccivcr. ucompound diaphragm comprising z: main sound-produ ing portion supported at its periphery and an auxiliary scuml-produciug portion :ulbstantinlly coextensive with the interior "of the receiver-casinq'. said auxiliary porlion being unsupported at its periphery and centrally secured to said main portion and otherwise free to move bodily toward and from the main portion.

4. In in telephone receiver, :1 compound diaphragm comprising a main sound-produciug portion and an. auxiliary sound-producing portion substantially coextensive with the interior of the receiver casino. said auxiliary portion being centrally secured thereto and otherwise free to move bodily toward and from the main portion, said main and auxiliary diaphragm portions being perforated to permit the free mssagc of air therethrough.

5. telephone receiver comprising it using, a magnetic system therein having a plurality of concentric elements Whose mugne'tic poles terminate in a common plane the adjacent poles being' of opposite polar ity, a main diaphragm restrained at its periphery, and an auxiliary diaphragm secured t0 the center of the main diaphragm and otherwise unrestrained, said auxiliary diaphingin being adjacent; to said plane magnetic poles.

ll. A. telephone receiver comprising a casing. a magnetic system therein having a plurality of concentric elements whose magnetic poles alternate inpolarity and terminate in u pommon plane. a main diaphragm i'estr ined at its peri 'ihcry in the walls of the casing. a chamber between said diuphrugm and the plane of said uuignelic poles. an auxiliary diaphragm Within said clizunlmand movable bodily toward and from said magnetic poles. and means connecting said main and auxiliary dinphragins.

i. A telephone receiver comprising a casing. a magnetic system therein comprising'u yoke plate and a plurality of concentric elements projecting: tlu-re'l rom having magnetic poles alternating in polarity and terminating in a common plane. magnetizing coils interposed between said concentric elements. a main diaphragm restrained at its periphery in the walls-o1 the casing and perforated to permit the passage of sound waxes. a chamber between said diaphragm and the plane of said magnetic poles, aultl an auxiliary diaphragm. Within said chamher centrally secured to said main diaphragm and otherwise free to move bodilg toward and from said magnetic poles.

ing coils interposed between said concentric elements, a main diaphragm restrained at its periphery in the walls of the casing, a chamber between said diaphragm and the plane of said magnetic poles, and an auxiliary diaphragm within said chamber centrally secured to said main diaphragm and otherwise free to move bodily toward and from said magnetic poles said main and auxiliary diaphragmsbeing perforated to permit the passage of sound Waves.

9. A telephone receiver comprising a magnetic system having a yoke plate and concentric rings projecting therefrom forming adjacent magnetic paths, magnetizing coils interposedbetween said rings and arranged to cause adjacent magnetic paths to be of 0pposite magnetic polarity, a main diaphragm restrained at itsperiphery, and an auxiliary V CHAS. 1i. CHURCH. Witnmses:

CHARLES N. MURRAY E. C. Brown. 

